How can I do that? Someone said use the prefix function but if I used that, would the user have to type in the prefix to use the webmail interface?

Would they have to type (prefix)_admin to log in? Is there a way they could use [email protected] as their username? I tried to put the full [email protected] into the username field but it wouldnt' take it...

Any advice will be helpful... just trying to figure this email out and then im good to go.

Please be detailed in your replies... Im a linux noob and I haven't been tinkering with ISPconfig long.

You mix up usernames and email addresses. There are 2 input fields in the interface, one for the username and one for the email address. Email addresses are unique for the domain and usernames are unique for the server. Thats why ISPConfig uses a username prefix and you should not deactivate it when you not now what you are doing! There is a reason that we activate it by default.

You will be able to login with the email address to the uebimiau webmail program. When you use outlook or thunderbird, you will ahve to use the username instead.

Linux usernames may never comntain a @ sign, thats why ISPConfig does not allow it. There are many threads about this topic, please use the search function in the forum if you need more information about this.